Valve arrangement for external-combustion engines



Sept 14 1943- D. M. wElGEl. 2,449,262

VLVE ARRANGEMENT FOR EXTERNAL-COMBUSTION ENGINES "UBLJV Wm D. M. WEIGEL`VALVE ARRANGEMENT FOR EXTERNAL-COMBUSTION ENGINES Filed Feb. 4, 1943 2sheds-sheet 2 INVENTOIL .DAN/EY4 M- WFE WM im wmv A rromvEYs PatentedSept. 14,' 11948 UNITED STATES PATENT OFFICE VALVE ARRANGEMENT FOREXTERNAL- COMBUS'VIION ENGINES Daniel Michel' Weigel, Detroit, Mich.

Application February 4, 1943, semi No. 474,611

' 8 Claims.

This invention relates to external combustion engines and particularlyto an improved injection type engine.

The principal objects of the present invention are to incorporate in aninjection engine operating on a constant volume combustion cycle, suchas that disclosed'in my Patent No. 2,364,330, issued December 5, 1944, agreater exibility and wider range of compression pressures withoutsubstantial increase in size or numberV of parts of the eng-ine; toprovide an improved and sim-` plied valve arrangement in which a singlesleeve valve controls communication of a combustion chamber with anintercooler and a power cylinder, and also controls inlet;v and outletvalves for each of two separate compression cylinders; and to providemeans to vary the 4amount ofair admitted from an intercooler to acombustion chamber in accordance with the opening of a throttle valve onthe intake of a compression cylinder supplying compressed air to theintercooler, so that the fuel injector pump and the air throttle may bedirectly coupled and varying quan# titles of air and fuel insubstantially constant proportions may be admitted tothe combustionchamber depending upon the position of thel throttle control.

Other objects and advantages will appear from the following detaileddescription of the preferred embodiment of the invention.

Referring to the drawings:

Fifi. 1 is a vertical sectional view of o ne cyl'- inder of an externalcombustion engine constructed according to the present invention;

Fig. 2 is an end view of the same; and

Fig. 3 is an enlarged sectional view of a fuel injector pump with adiagrammatic showing of the fuel piping. y

The engine illustrated'includes a cylinder block 5 having a crankcase 6secured to one end and supporting a crankshaft 1. A cylinder 8 is formedin the cylinder block and surrounded by alwater jacket B. The upper endof the cylinder is c'osed by a head IIl having a depending Waterjacketed portion II extending into the cylinder, and the lower end isclosedby a cover I2.

A valve sleeve I3 is slidably mounted within the cylinder 8 and extendsat its-upper end into the space between the cylinder 8 and the dependingportion Il of the head. .The cylinder cover I2 is formed with adepending skirt portion Il which is bolted at I5 to an annular flange I6depending from the cylinder block. The ilange I6 is slotted as shown atI1 and the 'lower end of the sleeve I3 is formed with a laterallyproiectmg lug is which works ni the not. |11. 'rire sleeve I3 slidablybears on the inner surface 'of the cylinder 8 and on the outer surfaceof the cylinder cover I2 and its skirt I4. l 'l A piston I9 providedwith suitable packing rings slidably bearsV within the sleeve I3 and 5formed as an auxiliary piston so as to bear y throughout itscircumference on the inner surface ofthe skirt I4 of the cylinder coverI2.. A

connecting rod 23 is journall'ed on a suitable wrist pin 24 carried bythe cross head 22 and at its other end is journalled to a crank pin 25of the crankshaft 1.

A suitable cam shaft 26 is arranged to be ydriven bythe crankshaft'l ata one-to-one ratio, as for example by a gear 21 on the crankshaft 1. anintermediate gear 28 and a gear 22 on the cam shlaft 28. The camshaft 2Bis formed with a crank =pin 30 to which is journ-alled a connecting rod3| which has its other end pivotally connectedto the lugr I8 projectingfrom the lower end of the sleeve I3. The crank pin 20 is arranged so asto reach its upper dead center about ahead of the crank pin 25.

A poppet valve 32 opens through the center of the cylinder head I0 andits depending extension I I. A suitable exhaust passage 33 is formed inthe head and is arranged to be opened to the interior of the, cylinder'8 when the poppet Valve 32 is open.I The valve 32 is operated by asultable rocker arm `and* push rod actuated by a cam 34 on the cam shaft26;

A combustion chamber 35 is formed" in` the cylinder block adjacent theupper end of the cyl'. inder 8. A port'36 is cutthrough thesleeve Il andis arranged to open the combustion chamber 35 to the interior of thecylinder 8 in one position of thesleeve I3. Similarly a port 311sarranged to open communication between the combustion chamber 35 and avpassage 138 in one position of the sleeve I3. Preferably the`combustion chamber is closed at its upper end by a plug 39 removablythreaded linto the cylinder block, as indicated at 40.

At its lower end the sleeve la is provided with -port openings Ilarranged to open communication between the interior of the 4cylinder onthe under side of the piston I9 and an air intake estates passage d,which may be formed as illustrated to partially or completely surroundthe cylinder. Another port t3 formed in the sleeve i3 is arrangedtovopen communication between an outlet passage 44 formedin the cylindercover I2 and a passage 45 leading to an intercooler f 45. Thus the underside of the piston I9 is arranged to inspire air through the intakepassage 42 and compress the same through the passages 44 and 45 into theintercooler 46.

Below the cylinder cover I2 the sleeve I3 is provided with a port 41arranged to open communication between another inlet passage 48 and theinterior of the skirt I4 above the cross-head 22. A port 45 formed inthe sleeve valve is arranged to open communication between the interiorof the sleeve I4 and a passage 55 which also leads to the intercooler45.

The various ports in the sleeve valve I3 are arranged so that as thepiston starts on its downward stroke from the position illustrated inFig. 1 the port 36 opens the combustion chamber 35 to the interior ofthe cylinder 5, the port 43 opens the interior of the cylinder 5 belowthe piston I5 to the passage 45 leading to the intercooler and the port41 opens the space between the crosshead 22 and the cylinder cover I2 tothe intake passage 45. These ports remain open substantially throughoutthe downward stroke of the piston I5. or in other words remain openduring the lower half of the reciprocation of the sleeve I3. As thecrank pin 25 passes its lower dead center the crank pin 35, whichv isleading the crank pin 25 by about 90, moves the sleeve I3 into the upperhalf of its reciprocation. This movement of the sleeve I3 closes theports 36, 43 and 41 and opens the ports 4I and 45 so as to establishcommunication between the intake passage 42 andthe interior of thecylinder 5 on the under side of the piston I3 and also to establishcommunication between the passage 55 leading to the intercooler 46 andthe space between the cross head 22 and the cylinder cover I2.

The port 31 in the sleeve valve I3 is arranged to open the passage 36 inthe cylinder head to the combustion chamber for a short period duringthe upper half of the stroke of the sleeve I3 after theport 36 hasclosed the combustion chamber from the interior of the cylinder head.'

This occurs during the upward stroke of the piston, beginning, forexample, about 45 after bottom center and ending about 45 before topcenter. Thus communication between the combustion chamber and thepassage 35 is again closed by the sleeve before the port 35 again opensthe combustion chamber to the interior of the cylinder 5 on the downwardstroke of the sleeve.

The intercooler 46 may consist, as illustrated. of a casing 5I whichencloses a plurality of water tubes 52 communicating at one end with awater inlet 53 and at the other end with a water outlet 54, The airpassages 45 and 55 lead through feather valves 55 and 56 respectivelyinto the interior of the casing 5I so that the air passes around thetubes 52. v

The opposite end of the intercooler 45 opens into an air passage 51which communicates with the passage 35 in thecylinder head through thepressure 4regulating valve 55.y This valve conslsts of a. slidable plug59 normally pressed against a seat 65 by an adjustable spring 6I. Whenthe, plug 55v is positioned on the seat 65 its lower face is opened tothe air pressure in the passage 51 and one of its side surfaces closesthe port 52 leading to the air passage 38 in the cylinder head. Thus thevalve 55 normally closes communication between the outlet passage 51 ofthe intercooler 45 and the passage 36 in the cylinder head and openscommunication between these passages when the pressure in the passage 51exceeds the tension of the spring 5 i.

A fuel injector pump 65 is arranged to be driven so as to inJect fuelinto the combustion chamber 35 once during each reciprocation of thepiston. Conveniently the pump may be' connected directly to the camshaft 26 as illustrated in Fig. 2. Any suitable type of pump may beused. The illustrated embodiment consists of a casing 55 containing acrankshaft 51 driving a connecting rod 65 pivoted to a piston 65,v Thepiston reciprocates within a rotatably adjustable sleeve 15 which can beturned to different. angular positions by the arm 1I. An annular passage12 is fuel.

formed to surround the portion of the casing 55 containing the sleeve15, and is arranged to communicate with the interior of the sleevethrough an opening 13 cut through the wall of the casing 55. The sleeve15 is formed with a relatively narrow opening 14 arranged to registerwith the opening I3 in different angular positions of the sleeve 15. Theannular chamber 12 is connected through a pipe 15 to a fuel pump 16which draws fuel from a main tank 11, and is also provided with a returnpipe `15 leading back to the fuel tank 11. Thus when the pump 16 isoperated the annular chamber 12 is maintained full of The piston 59 hasan inclined upper face 15 which cooperates with the slot -14 in thesleeve 15 to vary the quantity of fuel pumped on each stroke dependingon the annular position of the sleeve 15. The interior of the casing 55above the piston 56 communicates through a check valve 55 with thepipe,.5l which leads to anin- .lector nozzle 52 opening into theinterior of the combustion chamber 35.

Assuming the space above the piston 55 has first been filled with liquidfuel, the piston on its down stroke draws in additional fuel from theannular chamber 12 through the opening 13 and the slot 14. On its upstroke fuel is returned from the interior of the sleeve 15 to theannular chamber 12 until the inclined upper face 15 of I the piston 69passes the upper edge of the slot 14. Through the remainder of theupward stroke of the piston fuel is .forced through the check valve.65and the pipe 5I into the combustion chamber 3,5, 'With the sleeve 15turned so as tov position the slot 14 as illustrated in Fig. 3, thepiston 56 moves but a short distance after passing the upper end of theslot 14 so that a rela-v tively small amount of fuel is pumped on eachstroke. By turning the sleeve 15 so as to position the slot 14 adjacentthe-opposite side of the opening 13 a greater portion of the stroke ofthe piston occurs after the upper edge of the pistonv has passed theupper edge of the slot 14 so that a larger quantity of fuel is pumped oneach stroke.

The air vintake passages 42 and 48 are provided with throttle valves 85and 85 respectively. The

- air outlet passage 55 is also preferably provided with a valve 51which in one position opens the passage 55 to the atmosphere through aport 55 and in another position closes the passage 55 from theatmosphere so that air forced thereinto must pass-through the checkvalve 56 into the intercooler 46. The throttle valve 65 and the arm 1Iwhich adjusts the position of the sleeve 15 in the fuel pump 65 may bemanipullated simultaneously engine is preferably proportioned so thatthe ratio between the displacement volume of the cylinder 8 on the underside of the piston I9 and the volume of the combustion chamber 35 isequal to the desired maximum compression ratio of the engine. Thedisplacement volume of the space within the skirt I4 and above thecross-head 22 may then be used as a supercharger to compensate for thereduction ofatmospheric pressur caused by increases in altitude.

To start the engine arranged in this manner the throttle 85 and thecontrol arm 1I ofthe fuel injector pump may be left in closed position,the valve 91 closed, the valve 96 opened and the engine turned over byany suitable starting motor until the desired maximum pressure isbuiltup in the intercooler 46. The valve 81 may then be opened so that thecross-head 22 pumps idly without load and the throttle 85 and injectorpump control 1I opened to admit air and fuel. Each upward stroke ofthepiston I9 inspires avquantity of air through the port 4I and thel airintake 42, the quantity depending upon the degree of opening of thethrottle valve 85. Each downward stroke of the piston forces theinspired air into the intercooler 46. By reason of the cooling of theair in the intercooler a substantial part of the heat of compression isremoved so that the pressure in the intercooler increases substantialvlyin `accordance with the law of isothermal compression. The tension ofthe spring 6I is set at some value in excess of atmospheric pressure andless than the maximum pressure that would be obtained by isothermalcompression of a volume f air equal to the displacement volume on theunder side of the piston I9 into the volume of the combustion chamber35. This can be a relatively high compresssion ratio since thecompression is not limited by the rise in temperature of the air whichoccurs in the adiabatic compression in the ordinary engine. Preferablythe compression ratio is on the order of 17 to l, a ratio such that ifthe compression were adiabatic thetemperature of the air would exceedthe ignition temperature of the fuel.

Preferably the tension of the spring 5I is ad- -justed to be butslightly less than the maximum compression pressure. After theintercooler 46 has been filled withV air at a pressure which justbalances the tension of the spring 6I, the additional quantity of airforced into the intercooler by any given stroke of the piston I9 raisesthe valve 58 against the tension of thespring 8| and holds the valveraised so that the outlet 51 of the intercooler is open through the port62 to the passage 98 in the cylinder head until a quantity of air equalto that forced into the intercooler hasvpassed out through the port 62.`During the next upward stroke of the piston I9 the sleeve valve I9closes the port 36, so that the combustion chamber 35 is separated fromthe -cylinder 9,

and thereafter opens the port 31 so that air can enter the combustionchamber 35 from the intercooler 46. Y As soon as a quantity of air equalin weightv to that forced into the intercooler on the A preceding strokeof the piston I9 has entered the combustion chamber 35 the valve 58 isagain closed by the spring 6I. Thereafter as the piston I 9 continuesits upward stroke the sleeve valve I9 closes the port 31 and fuel isinjected lnto the combustion chamberl through the .injector 82. Ataboutthe time the piston I'9 reaches its upper dead center the valve96Lis opened anc'. the combustible mixture in the chamber 95 is: firedby any suitable means, such as the spark plug 90. The exact relationbetween the firing ofthe mixture; the opening of the valve 98 and thepnsition of the piston I9 may be varied slightly to obtain the bestresults. Preferably the firing is linitiated before the piston I9reaches its top center ar. d the valve is opened before ignition iscomplete, so as to avoid building up too great a pressure in thecombustion chamber 95.

After the mixture in the chamber 95 has been ignitedand the valve 96 hasopened so as to establish communication between the combustion chamberand the interior of the cylinder 9, expansion of the gases forces thepiston I9 downwardly on its next stroke. Ata suitable point during thedownward movement of the piston I9, as for example'at between 40 and 60prior to bottom dead center, the cam 94 opens the exhaust valve 92 sothat thecylinder may blow down to or below atmospheric pressure beforethe piston I9 reaches its bottom dead center. After the ypressure in thecylinderv 9 and the combustion chamber 95 have been reducedsubstantially to atmospheric pressure, and at a point near the vbottomdead center of the piston I9, the sleeve valve I9 closes the port 96 sothat the combustion chamber 95 is again separated from the cylinder 8.During the upward stroke of the Ipiston I9 the exhaust valve 92 remainsopen -so that the exhaust gases in the cylinder 8 are swept the quantityof air inspired on the under side of the piston I9 and forced into theintercooler 46` on the preceding stroke. This in turn depends upon thesetting of the throttlelvalve 95. I'hus the `control 'II for the fuelinjector pump may be adjusted simultaneously with the movement of thethrottle valve 85. The pump will inject the correct :quantity of fuelinto the combustion chamber for the quantity'of air admitted from theintercooler 46. The response of the engine to changes of the throttlevalve 95 and the injector pump control 1I is thus substantiallyinstantaneous, regardless of the volume of air compressed in theintercooler 46.

The engine may then be supercharged to compensate for reductions inatmospheric pressure caused by an increase in altitude by closing thevalve 81 and opening the valve 86 in proportion to the reduction inatmospheric pressure.

The engine controls may also be arranged so that the compression spaceabove the cross-head 22 serves as an overcharger operating throughoutthe normal range of operation of the engine at sea level. For thispurpose the combustion chamber 95 is increased in size so that the ratioof its volumeto the combined volumes of the cylinder 8 lon the underside of the piston I9 and the displacement volume above the cross-head22 is equal to the desired compression ratio. The valve 81 is thenmaintained closed and the throttle valves 85 and 86 and the .control 1Ifor the fuel injector pump Iare manipulated. The fuel injector pump isarranged to supply a greater quantity of fuel at any particular settingto conform to the greater quantity of air compressed y the correctamount for the particular length of stroke and diameter of skirt idincluded in the engine. v

, Although a preferred embodiment of the invention has been described itwill be understood that the invention is not limited thereto. Thepressure regulating valve, for example, may be used -either in theengine disclosed, or in an engine such as that shown in my Patent No.2,220,- 926, in which a combustible mixture of fuel and air iscompressed into the intercooler. Similarly, other variations andrearrangements of the parts may be resorted to without departing fromthe scope of the invention as defined in the following claims. n

I claim:

1. In combination with an external combustion engine having a combustionchamber, a reservoir of compressed gas, means driven by the engine forcompressing gas into said reservoir, a throttle valve controlling thepressure of the gas compressed by said means, a conduit for admittinggas from said reservoir into said combustion chamber, a valve operatedby said engine interposed in said conduit, a pump for injectingcontrollable quantities of fuel into said combustion chamber, aregulating valve in said conduit interposed between said reservoir andsaid first named valve, and means exertinga constant pressure on saidregulating valve urging the same toward closed position to interruptcommunication between said reservoir and said engine, said regulatingvalve being urged toward open position by the pressure in saidreservoir.

2. In combination with an external combustion engine having a combustionchamber, a reservoir ofV compressed gas, means driven by the engine forinspiring and compressing gas into said reservoir, a throttle valvecontrolling the pressure of the gas inspired by said means, a, valveoperated by said engine for admitting gas from said reservoir into saidcombustion chamber once during each cycle of the engine, a pump forinjecting fuel into said combustion chamber once during each cycle ofthe engine, a regulating valve interposed between said reservoir andsaid engine, and means exerting a constant pressure on said regulatingvalve urging the same toward closed position to interrupt communicationbetween said reservoir and said engine, said -regulating valve beingurged toward open position by the pressure in said reservoir. 4

3. An external combustin engine comprising a main cylinder, adouble-acting piston reciprocable in said cylinder, an auxiliarycylinder aligned with said main cylinder, means closing the adjacentends of said main and auxiliary cylinders, a cross-head reciproeable insaid auxiliary cylinder, a piston rod connecting said piston with saidcross-head and extending through said closure means, a combustionchamber having a I removable plug adapted to be varied in length to varythe volume of said chamber, an intercooler, valve means arranged to openone end of said main cylinder alternately to a gas intake and to saidintercooler, valve means to open said auxiliary cylinder alternately tosaid intercooler and to a gas intake, a check valve interposed betweensaid intercooler and said auxiliary cylinder, a second check-valveinterposed between said intercooler and said end of said main cylinder,valve means to open said combustion chamber alternately tov saidintercooler and to the other end of said main cylinder, and valve meansto open saidauxiliary cylinder to atmosphere to render the sameinoperative when desired.

4. An external combustion engine comprising a main cylinder having powerand compression ends, a double-action piston reciprocable in saidcylinder, an auxilairy cylinder aligned with said main cylinder,meansclosing the adjacent ends of said main and auxiliary cylinders, acrosshead piston reciprocable in said auxiliary cylinder, a piston rodconnecting said double-actingv piston and said cross-head piston andextending through said closure means, an intercooler, valve meansarranged to open the compression end of said main cylinder alternatelyto an air intake and to said intercooler, valve means to open saidauxiliary cylinder alternately to said intercooler and to an air intake,check valve means between said auxiliary cylinder and said intercooler,check valve means between the compression end of said main cylinder andsaid intercooler, a combustion chamber, valve means to open saidcombustion chamber alternately to said intercooler and to the power endof said main cylinder, pressure regulating valve means between saidcombustion chamber and said intercooler, a pump for injecting fuel intosaid combustion chamber once during each cycle of said engine while saidcombustion chamber is closed from said intercooler and from the powerend of said main cylinder, and ignition means in said combustion chamberarranged to initiate tiring of the mixture in said 'combustion chamber,while said combustion chamber is closed from said intercooler and fromthe power end of said main cylinder.

5. An external combustion engine comprising 'a main cylinder having-power and compression ends, a double-acting piston reciprocable in saidcylinder, an auxiliary cylinder aligned with said main cylinder, meansclosing the adjacent ends of said main and auxiliary cylinders, acrosshead reciprocable in said auxiliary cylinder, a piston rodconnecting said piston with said crosshead and extending through saidclosure means, a combustion chamber, an intercooler, and a sleeve valveslidably mounted within said main cylinder and surrounding saidauxiliary cylinder, said sleeve valve having ports arranged to open thecompression end of said main cylinder alter-- nately to an air intakeand to said intercooler, a feather valve interposed between saidintercooler and the compression end of said main cylinder, ports to opensaid auxiliary cylinder alternately to said intercooler and to an airintake, a second feather valve interposed between said intercooler andsaid auxiliary cylinder, ports to open said combustion chamberalternately to said intercooler and to the power end of said maincylinder, a pressure regulating valve interposed between saidintercooler and said combustion chamber, and a Dump for injecting fuelinto said combustion chamber after said combustion chamber has beenclosed from said intercooler and before said combustion chamber isopened to the l main cylinder, means closing the adjacent ends of saidmain and auxiliary cylinders, a cross-head reciprocable in saidauxiliary cylinder, a piston rod connecting said piston withsaidcross-head and extending through said closure means, a combustionchamber, an intercooler, a pressure regulating valve interposed betweensaid intercooler and said combustion chamber, and a sleeve valveslidably mounted within said main cylinder and surrounding saidauxiliary cylinder, said sleeve valve having ports arranged to open thecompression end of said main cylinder alternately to an air intake andto said intercooler, ports to open said auxiliary cylinder alternatelyto said intercooler and to an air intake, ports to open said combustionchamber alternately to said intercooler and to the power end of saidmain cylinder, a pump for injecting fuel into said combustion chamberafter said combustion chamber has been closed from said intercooler andbefore said combustion chamber is opened to the power end of said maincylinder, and ignition means arranged to initiate ring of the mixture insaid combustion chamber prior to the opening of said combustion chamberto the power end of said main cylinder.

7. In an external combustion' engine of the fuel injection type, acombustion chamber, a reservoir for compressed air, means driven by theengine for compressing air into said reservoir, a pump driven by saidengine for injecting fuel into said combustion chamber, means forcontrolling the quantity of fuel injected into said combustion chamber,a conduit for admitting air from said reservoir into said combustionchamber, a valve operated by said engine in said conduit, a second valveinterposed between the first named valve and said reservoir., meansexerting` a constant pressure on said second valve urging the sametoward closed position to interrupt communication between said reservoirand said combustion chamber, said second valve being urged toward openposition by the pressure in said reservoir and means for controlling thequantity of air compressed into said reservoir independently of thecontrol of said pump, whereby air pressure suiilcient to open saidsecond valve may be built up in said reservoir before fuel is admittedto said combustion chamber to start the engine.

8. An external combustion engine comprising a main cylinder having power`and compression ends, a double-acting piston reciprocable in saidcylinder, an auxiliary cylinder aligned with said main cylinder, meansclosing the adjacent ends of said main and said auxiliary cylinders, acrosshead reciprocable in said auxiliary cylinder, a piston rodconnecting said piston with said crosshead and extending through saidclosure means, an intercooler, valve means arranged to open thecompression end of said main cylinder alternately to an air intake andto said intercooler, valve means to open said auxiliary cylinderalternately to said intercooler and to an air intake, a comf bustionchamber, means for injecting fuel into said combustion chamber, valvemeans to open tercooler and to the power end of said main cylinder, aregulating valve interposed between said intercooler and said combustionchamber, and means exerting a constant pressure von said regulatingvalve urging the same toward closed position, said regulating valvebeing'urged toward open position by the pressure in said Intercooler.

DANIEL MICHEL WEIGEL.

REFERENCES CITED The following references are of record inthe file ofthis patent:

UNITED STATES PATENTS Number Name Date 753,086 Mains Feb. 23, 19041,237,373 Nordberg Aug. 21, 1917 1,301,036 Cage Apr. 15, 1919 1,386,394Cager Aug. 2, 1921 1,393,831 l Rossman Oct. 18, 1921 1,518,983 HyvernaudDec. 9, 1924 1,878,326 Ricardo Sept. 20, 1932 1,955,620 Bchi Apr. 217,1934 2,131,216 Brooke Sept. :27, 1938 2,220,926 Weigel Nov. 12, 19402,227,896 Fitzgerald Jan. 7, 1941 FOREIGN PATENTS Number Country Date611,212 France June 28, 1926 219,469 Germany Feb. 28, 1910 247,745Germany June 6, 1912

